Deficiency of enzyme in Tay-Sach disease ?
**Core Concept**
Tay-Sachs disease is a rare, inherited disorder caused by a deficiency of a specific enzyme involved in the breakdown of fatty substances within cells, leading to accumulation of toxic compounds and cellular damage.
**Why the Correct Answer is Right**
The correct answer is Hexosaminidase A (Hex-A), an enzyme responsible for breaking down GM2 gangliosides in neurons. Deficiency of Hex-A leads to the accumulation of GM2 gangliosides, causing neuronal damage and death. This results in the characteristic clinical features of Tay-Sachs disease, including progressive neurological deterioration, muscle weakness, and seizures.
**Why Each Wrong Option is Incorrect**
* **Option A:** Beta-Galactosidase is an enzyme involved in the breakdown of gangliosides, but its deficiency is associated with GM1 gangliosidosis, a different lysosomal storage disorder.
* **Option B:** Arylsulfatase A is an enzyme involved in the breakdown of sulfated lipids, and its deficiency is associated with metachromatic leukodystrophy, a demyelinating disorder.
* **Option C:** Alpha-Galactosidase is an enzyme involved in the breakdown of galactosylceramides, and its deficiency is associated with Fabry disease, a lysosomal storage disorder characterized by pain, skin lesions, and kidney failure.
**Clinical Pearl / High-Yield Fact**
Tay-Sachs disease is an autosomal recessive disorder, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to express the disease.
**Correct Answer:** B.